Air cleaner and silencer



March 12, 1935. G, Q RENS|NK 1,994,006

AIR CLEANER AND SILENCER Filed Feb. 17, 1934 145x107 vz ily.

Patented Mar. 12, 1935 UNITED ,STATES PATENT OFFICE 12 Claims.

My invention relates to an improved air cleaner and silencer.

The main object of the invention is to provide an air cleaner and silencer for internal combustion engines which is adaptable for ,either up draft or down draft carburetors, and in which the air cleaner is in the form of a detachable unit which can be easily and quickly removed or installed.

Further, it is an object to provide a device of this character in which a tapered cylindrical or frusto-conical vertically disposed air cleaner is employed which is self-cleaning under the vibratory action of the engine and therefore cannot become clogged. The cleaner is held within and spaced from a casing in which the air always enters from the bottom for either up draft or down draft carburetors. The cleaner is clamped between the top of the casing and a bottom plate of less diameter than the casing, this plate being provided with a central aperture for the reception of an air outlet pipe; when the device is used on down draft carburetors, the pipe is inserted in a similar hole in the top of the casing when the device is used on an up draft carburetor. The air from the cleaner passes between two horizontal bodies of pervious sound absorbing material confined within perforated retainers that are reversible with respect to the said top and bottom plates.

These and other objects which will hereinafter appear are accomplished in the manner set forth in the accompanying drawing, in which:-

Fig. 1 is a view partly in side elevation and partly in section, showing the improved device as arranged for attachment to a down draft carburetor.

Fig. 2 is a similar view, the device being arranged for attachment to an up draft carburetor, a slight modification being shown in the construction of one of the members.

`Referring to the accompanying drawing: The letter A refers to a cylindrical casing which is open at the bottom, the top being slightly bulged and provided with a. central aperture 1 which is formed in a depressed portion of the top which forms a flared surface 2 surrounding the aperture 1. The top is also formed with an annular shoulder 3 near its circumferential edge, and with a groove 4 coincident with its edge in which rests the upper edge of an air cleaner 5, the lower edge of which rests in a corresponding circumferential groove 6, which is formed in a bot'- tom plate '7, which is also provided with an annular shoulder 8 in vertical line with the shoulder 3 in the top of the casing, and with a central aperture 9 of the same diameter as the aperture 1 in the top of the casing. The bottom plate is of considerably less diameter than the casing and is clamped against the lower edge of the air cleaner in a manner to be presently described. The air cleaner inclines outwardly toward its upper edge, and comprises two sheets of coarse mesh wire netting between which is placed one or more sheets of a suitable air cleaning material, preferably filter paper. As each of the wire netting members is frusto-conical and has its ends connected, the placing of the outer member over the filter paper automatically clamps the same against the inner member, thus dispensing with any form of fastening means. The upper and lower edges of the two members may be pinched together so as to maintain them in clamping relation upon the lter paper. Since the air cleaner inclines outwardly toward its upper edge, clogging of the cleaner is automatically prevented, as the vibratory action of the engine when operating will cause the dust and other foreign substances to drop away from the cleaner and pass out through the open bottom of the casing.

In Fig. 1 of the drawing the device is arranged for attachment to a down draft carburetor, but the same parts or members are used for each arrangement of the device. These parts comprise an air outlet pipe 10, a horizontally disposed concavo-convex perforated' plate 11, having a central aperture, a horizontally disposed perforated concavo-convex plate 12 spaced from the plate 11 and forming therewith an air inlet space communicating with the pipe 10, an outer imperforate plate 13, a perforated cylinder 14, and clamping means, comprising a dished disk l5, a bolt 21`and anut 22, as will now be fully set forth: In Fig. '1, the outer plate 13 rests within the annular shoulder 3 in the top of the housing and is provided with a right angled flange or lip 18, which surrounds the adjacent end of the perforated cylinder 14, this end being the upper end in this arrangement of the device. The lower end of the cylinder 14 is formed with a narrow inturned flange 19 which rests within the annular shoulder 8 of the bottom plate 7 and is welded to the said plate. A disk 20 is welded or otherwise secured to the central portion of the plate 13 and a bolt 21 having a relatively large i flat head is passed through a hole in the disk and plate and its head is secured to the said disk. The cupped disk is seated in the depression in the top of the casing and covers the aperture 1 in said depression, and is provided Witha hole to receive the bolt 21 and when the nut 22 is screwed down against the disk 15, the bottom plate '7 is drawn upon and clamps the air cleaner 5 between itself and the topv of the casing, Vas will be understood by reference to Fig. 1 of the drawing.

'I'he perforated plate 12 is separated from the plate 13 by a relatively wide space and its rim portion is outwardly curved, its edge resting upon an annular bead 23 which is formed on the wall of the cylinder 14 and is welded thereto. The space between the plates 12 and 13 is filled With a suitable pervious sound absorbing material 24.

'Ihe perforated plate 11 is separated from the plate 12, by a relatively wide space which constitutes the air inlet space from the air cleaner. This plate is similar tothe plate 12, in that its circumferential portionis outwardly curved and its edge bears upon an annular bead 25 on the wall of the perforated cylinder 14 and is soldered or welded thereto, but it is formed with a central aperture, the metal surrounding the aperture being pressed outward to form a short neck 26 in which is inserted the inner end of the air outlet pipe 10. This pipe is inserted through the hole 9 in the bottom plate 7, themetal surrounding the hole 9 being inwardly depressed or flared, and the outer end portion of the pipe is slightly enlarged thereby forming a ared shoulder 27 which bears against the said flared portion of the bottom plate and is Welded thereto, the enlarged end of the pipe being adapted to t upon the outlet end of a carburetor. The space inclosed by the plate 11, the bottom plate '7, the cylinder 14 and the pipe l0 is filled with a pervious sound absorbing material 28.

It will thus be seen that the air drawn into the carburetor through the air cleaner 5, enters the space between the plates 11 and 12 and passes out through the pipe 10. The cylindrical air cleaner provides a large screen surface which permits an ample air supply to the carburetor, a portion of the air passing through the sound silencing material, and the sound vibrations from the engine pass up through the pipe 10 and into the space between the plates 11 and 12 and through the said plates to the two bodies of sound silencing material, where the sound is suppressed by absorption and practically eliminated.

When the device is to be used in connection with an up draft carburetor, the position of the casing AXremains the same, but the position of the perforated cylinder 14 to which are secured the plates 11, 12, and 13, is reversed and the plate 13 then lies within the annular shoulder 8 of the bottom plate 7 and the inturned flange 19 on the opposite end of the cylinder lies Within the shoulder 3 on the top of the casing and is welded thereto. The cupped plate is seated in the depression in the bottom plate 7, thus covering the aperture in the plate, and the bolt 21 carried by the plate 13 passes through the hole in the said cupped plate and receives the nut 22 which is screwed againstthe cupped plate, thus clamping the air cleaner between the bottom plate and the top of the casing. The air pipe 10 is inserted through the aperture in the top of the casing and into the neck 26 of the plate 11 and its shoulder 2'7 is welded to the flared portion 2 surrounding the said hole in the top of the casing.

The frusto-conical form of the air cleaner provides a large screen surface which permits an ample air supply yto the carburetor under all engine conditions without causing any material increase in resistance to the now, the velocity of the inrushing air is broken by the perforated cylinder 14 through which the air must pass, and the space between the plates 11 and 12 constitutes an expansion chamber for the sound vibrations Which are suppressed by absorption in the interstiees of the sound absorbing material.

Attention is called at this time to the fact that the perforated plates or diaphragms 11 and 12 have annular radially convex surfaces adjacent their outer edges and that the extreme outer edges are curved away from each other so as to form an air entrance opening that has the general shape of a venturi and which has been found to improve the sound absorbing properties. The self-cleaning feature, which is dependent on the frusto-conical shape of the air cleaner screen is, of course, not dependent on the .presence of the air absorbing pads 24 and 28 although the ultimate object of air cleaning and sound absorption requires both elements.

In Fig. 2 of the drawing, a slight modification is shown in the construction of the perforated cylinder, which consists in providing the central portion thereof with a circular series of large openings 14A coincident with the space between the horizontal plates or diaphragms 11 and 12. These openings are sufcient to prevent any restriction of the air passing into the space between the plates and thence through the pipe 10 to the carburetor.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In an air cleaner and silencer of the character described, a circular casing open at its bottom end, a circular air cleaner supported in said casing and spaced therefrom, a perforated cylinder within said4 air cleaner and spaced therefrom and closed at one end, a horizontal perforated diaphragm in said cylinder and pervious sound absorbing material filling the space between said diaphragm and said closed end, a second diaphragm spaced from the first diaphragm and having a central aperture, a member closing the other end of the cylinder and having a central aperture, an air outlet pipe extending through the aperture of the said closing member and into the aperture of the second diaphragm, and pervious sound absorbing material in the space between the second diaphragm and the closing member.

2. In an air cleaner and silencer of the character described, a cylindrical casing open at one end and having a central aperture in its closed end, a circular air cleaner in the casing and spaced therefrom, a perforated cylinder within and spaced from the air cleaner and closed at one end, an end plate in the open end of the casing which closes the other end of the cylinder and is provided with a, central aperture and is of greater diameter than the cylinder, the air cleaner being supported between the end plate and the closed end of the casing and means for clamping the air cleaner between these parts, spaced horizontal perforated diaphragms secured within the cylinder one of which has a central aperture, an air outletJ pipe inserted in said last named aperture and extending out of the casing, and pervious sound absorbing material in the spaces enclosed by the perforated cylinder, the diaphragms and the end members of the cylinder.

3. In an air cleaner and silencer of the character described, a cylindrical casing open at one end and having a central Iaperture in its closed end, an end plate in the open end of the casing and of less diameter than the casing, having a central aperture, a perforated cylinder within and spaced from the casing, having a closed end and spaced perforated horizontal diaphragms secured therein one of which has a central aperture, said cylinder being reversible and its open end being secured either to the closed end of the casing or the said end plate, an air outlet pipe in the apertured diaphragm which extends out through the aperture in the adjacent end member, a disk for covering the aperture in the other end member, a bolt extending through the closed end of the cylinder and said disk and a nut thereon, thereby to support the end plate in either position of the cylinder, a circular air cleaner surrounding the cylinder, and spaced from the same and from the casing and held between the end plate and the closed end of the cylinder, and pervious sound absorbing material in the spaces enclosed by the cylinder, the diaphragms and the end members of the cylinder.

4. In an air cleaner and silencer of the character described, a cylindrical casing open at the bottom and having a central aperture in its end, a bottom plate in the open end of the casing and of less diameter than the casing and having a central aperture, a circular air cleaner in the casing and spaced therefrom and held between the bottom plate and the end of the casing and inclined outwardly towards its upper end, a perforated cylinder within and spaced from the air cleaner and having spaced horizontal perforated diaphragms and a closed end,.one of said diaphragms having a central aperture, said cylinder being reversible, its open end being secured either to the bottom plate or the end of the casing according to its position, an air outlet pipe extending from the apertured diaphragm through the aperture in the adjacent end member, a disk over the aperture in the other end member, means connecting the disk and the closed end of the perforated cylinder thereby to support the bottom plate in either position of the cylinder, and bodies of pervious sound absorbing material in the spaces above one diaphragm and below the other diaphragm.

5. In an air Icleaner and silencer of the charac ter described, a cylindrical casing open at its lower end, a perforated cylinder within and spaced from said casing, spaced horizontal perforated diaphragms in said cylinder, one of which has a central aperture, an air outlet pipe extending from said aperture, a frusto-conical air cleaner surrounding the cylinder and spaced from the same and from the casing, the larger end of the cleaner being at the top, said cylinder being closed at its upper end by the casing and having a plate over its lower end, said plate also closing the lower end of the air cleaner, and pervious sound absorbing material in the spaces above one diaphragm and below the other diaphragm, the air pipe passing through one of the spaces containing sound absorbing material and communicating with the chamber between the two bodies of sound absorbing material.

6. Mechanism according to claim 4 in which the air cleaner comprises two sheets of coarse wire netting of tapered cylindrical form and one or more sheets of lter paper which are disposed between the wire netting cylinders, thereby providing an air cleaning unit.

'7. Mechanism according to claim 4 in which the central portion of the perforated cylinder is formed with a circular series of large openings coinciding with the space between the diaphragms.

8. In mechanism of the character described, a cup shaped circular casing open at its lower end, a circular perforated wall within and spaced from the casing and having a closed end, means for securing said wall to the upper end of the casing, a bottom plate secured to the lower end of the wall and extending beyond the same but of less diameter than the casing, said bottomplate having a central aperture, spaced horizontal perforated plates within the wall and secured thereto, the lower perforted plate having a central aperture, an air pipe inserted in said aperture and extending out through the aperture in the bottom plate, air penetrable sound silencing material in the space above one perforated plate and in the space below the other plate, and a frusto-conical air cleaning unit held between the bottomvplate and the top of the casing and spaced from the casing and the perforated wall, the larger end of the cleaning unit being at the tcp.

9. Mechanism according to claim 8 in which the end of the casing and the bottom plate are formed with annular shoulders to confine the ends of the perforated wall, and with annular grooves to receive the edges of the frusto-conical air cleaner.

l0. In mechanism of the character described, a circular casing open at its bottom end and having a central opening in its closed end, a bottom plate of less diameter than the casing, a perforated cylinder having a closed end, spaced horizontal perforated diaphragms one of which is formed with a central aperture, said cylinder being reversible with respect to the bottom plate and the end of the casing, means for securing said cylinder within the casing, a pipe extending from the apertured diaphragm through the adjacent end member, means for closing the aperture in the other -end member, a frusto-conical air cleaner in the space between the perforated cylinder and casing wall and closed at its ends, the larger end of the air cleaner being at the top and air penetrablesound silencing material in the space above one diaphragm and below the other diaphragm.

1l. An air cleaner, comprising in combination a cup-shaped casing having a substantially cylindrical wall and its open end at the bottom, a frusto-conical air cleaner screen located in the casing with its larger end at the top and connected with the casing at its upper end; a closure for the lower end of the air cleaner enclosed by said screen, the space within the air cleaner screen being divided into an annular' compartment and a cylindrical compartment by a foraminated cylindrical partition, the cylindrical compartment being divided into three circular compartments by means of two perforated horizontal diaphragms, sound absorbing material in the upper and lower compartments, and an air outlet pipe in communication with the middle compartment.

12. An air cleaner in accordance with claim 1l, in which the outer edges of the horizontal diaphragms are curved away from each other so as to form rounded inwardlyv tapering walls which reduce'the resistance to air ow.

GEORGE C. RENSINK. 

